Tanning solution



I added are dissolved in liters of water.

Pat'ented Qct. 17. 1933 ED STATES rarest stam- 1,930,910 a r TANNING SOLUTION Otto Riihm, Darmstadt, Germany NoDrawing. Application May 15, 1928, Serial V No. 278,045, and in Germany June 20, 1927 9 Claims. (01. 149- 5) I have filed an application for patent in Germany on June 20, 1927. i j i My invention relates to mineral tannage; and I consists in the discovery that salts of iron, or 5 chromium, or aluminum, or several salts of these,

1 on the one hand, andphosphoric acid or acids of arsenic, or salts or esters of said acidscan be advantageously employed for mineral tannage.

To name some of the salts, by way of example, I would mention in the first place, the chlorides and sulfates, whereas or the salts of phosphoric acid I would mention the sodium phosphate and of the. esters, for instance, the glycerinefiphosphoric acid, eventually in combination with alkali .15 or alkaline earth metals. I

. Example 1 20 kilogrammespf iron sulfate chloride fto which 1 kilogramme of phosphoric acid has been To this are added, while the solution is continually stirred,]l70 liters of water wherein are contained 4.2 kilogrammes of neutral sodium carbonate. With this tanning liquor 100 kilogrammes of pelts are'tannedfiby being moved around for 6 130 8 hours in the tanning-vessel. 1 i.

' Example 2 5 kilogrammes of alum, to which are added 3 kilogrammes of common salt and 0.5 kilogrammes of glycerine. phosphoric acid are dissolved in-l00 liters of water, and in this solution 100 kilogrammes of pelts are tanned by being moved around for 6 to 8 hours in the tanning vessel. j

Example 3;

20 kilogrammes of iron sulfate chloride are dissolved in 25 liters of water to which have been i added 1.75 kilogramme of glycerine'phosphoric 40 acid. After the solution is completed 170 kilogrammes of a.1.8% soda solution are added duringstirring. Inthis solution 100 kilogrammes of pelts are. tanned by being moved around in the tanning vessel for 6-8 hours. .Erample 4' I V 10 kilogrammes, of crystallized chromium chloride are dissolved in 100 liters of water to which 3 kilogrammes of common salt have been added.

To this solution ,I add 0.3kilogramme of 100% anhydrous glycero phosphate of sodium and gradually 2 kilogrammes of calcinated soda during stirring. In this liquor 100 kilogrammes of pelts are tanned by being moved in the tanning vessel for 4-6 hours.

" phosphoric acid.

containing a trivalent cation esters of phosphoric acid.

chloride and phosphoric acid.

The phosphoric acid, or the acids of arsenic, or the corresponding salts or esters can be added either during the tanning operation, or can be used already in the pickle, or they can be used in the stumn'g. I

There is already known a chromium two-baths tanning-process, in'which arsenic salts. are used,

which process I expressly disclaim. Alsotanning processes have been described in which iron and chromium compounds as well as pyro-phosphates 5 are used, in which processes it is necessary to also use boron, wherein said processes differ from my process.

What I claim is: 1. A tanning solution, comprising iron salts containing atrivalent cation, and esters of phosphoric acid.

2. A tanning solution, comprising chromium salts containinga trivalent cation, and esters of v i q '75 3. Atanning solution, comprising aluminum salts containing a trivalent cation, and esters of phosphoric acid. t

4. A tanning solution, comprising. ironsalts and salts of the 0 5. A tanning solution, comprising chromium salts containing a trivalent catiornand salts of the esters of phosphoric acid.

'6. A tanning solution, comprising aluminum 35 salts containinga trivalent cation, and salts of the esters of phosphoric acid.

7'. A tanning solution, comprising iron sulfate 

